Fluid-pressure brake



(No Model.)

' H. S. SMITH.

FLUID PRESSURE BRAKE.

110.591,701. Patented 001. 12,1897.

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WTNESSES BY Y ATTORNEYS.

UNITED STATES PATENT OEEIQE.

HERBERT-S. SMITH, OF SAN JOS, CALIFORNIA.

FLUID-PRESSURE BRAKE.

SPECIFICATION forming part of Letters Patent No. 591,701, dated October 12, 1897. Application filed December 9, 1896. Serial No..6l4,984. (No model.)

certain new and useful improvements in fluid-` pressure brakes whereby an engineer is enabled to release the whole orany portion of` the fluid in the train-pipe and still have the initial force to apply the brakes, the live fluid in the auxiliary reservoir being used over andv over again for applyingthe brakes, the latter being automatically applied in case a train should break apart.

The invention consists of certain parts and details and combinations of the same, as will be fully described hereinafter and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in both the gures'.

Figure l is a sectional plan view of the improvement; and Fig. 2 is a similar view of part of the same, with parts in a different position.

The train-pipe A is connected in theusua manner with a uid-pressure supply and contains an engineers valve of any approved construction. The train-pipe A is connected under each car by a branch pipe B, having 5o the release position shown in Fig. l.

an angle-cock B', with the outer end of the brake-cylinder O, in which reciprocates a piston D, having its piston-rod D connected with a brake-lever E, connected with the brakebeam for applying and releasing the brakeshoes to and from the car-wheels.

The inner end of the cylinder O is connected with the open end of an' auxiliary reservoir F, as is plainly indicated in Figs. 1 and 2, the said reservoir being somewhat larger in diameter, as indicated. A feed-groove C is formed on the inner end of the cylinder O to permit fluid under pressure entering the cylinder C by the pipe B to pass through the said feed-groove C at the time the piston D i 1ilu fluid under pressure passingthrough the feedgroove C can then pass through a port F to the inner end of the reservoir F, the said port F being controlled by a piston-valve G, having a limited sliding motion between the inner end of the cylinder C and the brackets F2 inside of lthereservoir F.

The forward face of the piston-valve G is formed With` a valve-seat G', Yon which is adapted to be seated a leather-covered valve D2, secured on the stem'D and forming part of the piston D, so as to move with the latter. The seat G forms an annular space F3 in front of the valvefG and within the reservoir for the passage of the fluid from the feed-groove C to the port F', as previously described, so that when the several parts are in the position indicated in Fig. l the uid under pressure from the train-pipe A can pass by the pipe B into thecylinder C, through the feed-groove C' into the annular space F3, and to and through the port F' to the inner end of the auxiliaryv reservoir F, so as to charge the latter until the pressure in both the brake-cylinder and the auxiliary reservoir is equal.

When it is desired to apply the brakes, the engineer exhausts the airfrom the train-pipe A in the usualmanner, and in doing so reduces the pressure in front of the brake-cylinder O, so that the preponderance of pressure in the auxiliary reservoir F causes a forward sliding of the piston valve G and a similar movement of the valve D2 and piston D, so that the latter moves beyondv the beginning of the feed-groove O to disconnect the front and rear ends of the brake-cylinder O. A further reduction of pressure in the train-pipe A causes the preponderance of ypressure in the auxiliary reservoir F to unseat the valve D2 from the piston-valve G,

whereby the fluid under pressure can pass through the valve-seat opening G2 into the inner end of the brake-cylinder O, so as to act on the piston D and apply the brakes in the usual manner. It is understood that when the piston-valve G moves forward it closes the port F to disconnect the brake-cylinder and auxiliary reservoir at this point.

When it is desired to release the brakes, the engineer sends fluid under pressure through IOO the pipe A and pipe B into the outer end of C and the port F are again uncovered. The

several parts are nov7 again in position for applying the brakes whenever a reduction of pressure takes place in the outer end of the brake-cylinder C.

It is evident that by the arrangement described the charge in the'auxiliary reservoir F is permanent and is used over and over again for applying the brakes as the piston D is forced into a release position by the live fluid entering the outer end of the cylinder C, but the application of the brakes is .by means ofa charge'permanently contained in the auxiliary reservoir and acting on the piston D to apply the brakes, as above described.

The piston-rod D is formed with an extension D3, passing through the opening Gr2 into the auxiliar reservoir F and on'the outer end of this piston-rod extension D3 presses a coil-spring H, resting on` the brackets F2,previously mentioned. -A release-valve I is connected with the port F', so that when a car is detached and the brakes are applied and it is desired to release the brakes then the operator, by manipulating the release-valve I, permits the fluid under pressure to pass out of the auxiliary reservoir F,and the spring l-I then pulls the piston D back into a release position to release the brakes. In the bottom of the brake-cylinder C is a drainplug J, as shown in Fig. l.

Now it will be seen that byl the arrangement described the brakes are automatically applied in case a train breaks in parts, as the air Vthen escapes from the pipe B and the outer end of the brake-cylinder C, and the permanent charge in the auxiliary reservoir F acts on the piston D, as above explained, to apply the brakes.

It will further be seen that the device is very simple and durable in construction, -the triple valve isv entirely dispensed with, and the device is not liable to get out of order, and'it is under the full control of the engi-1 neer, who can apply the brakes and release any quantity ofthe air from the train-pipe, according to the force with which he desires to apply the brakes, it being always understood that the permanent charge in the aux Viliary reservoir retains its initial pressure,

and a recharging thereof is not necessary It is evident that a large amount of airis thus saved, as a recharging of the auxiliary reservoir is not required.

It -will be vseen that by the arrangement above Vset forth no air is discharged under the car, and consequently the hissing sound upon releasing the brakes by systems as now employed is entirely avoided, as the only discharge of air takes place at the engineerfs valve.

The engineer has full control of releasing any portion of the brake force that he may desire, retaining the amount of pressure that he may desire to regulate his rate of speed without the use of the retaining pressurevalve attached to the triple valve which is now generally in use and which is not under the control of the engineer.

upon one side of the piston D than on the other will move this piston back until the forces become equalized. Therefore no leak- 'age of air will take place from the auxiliary reservoir to the brake-cylinder and will always have the initial force to apply the brakes, and can be repeatedly released and applied with as much force on the last application as was exerted on the first application.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. The combination of the brake-cylinder, the piston therein, the auxiliary reservoir connected to one end of said cylinder, the piston-valve arranged in said reservoir and adapted to engage the piston, the cylinder having a feed-groove whereby air may get past the piston, and the auxiliary reservoir having a port or channel whereby the air may get past the piston-valve, substantially as described.

2. The combination of the brake-cylinder, the piston arranged therein and carrying a valve, the auxiliary reservoir connected to the cylinder, the piston-valve in said reservoir, said piston-valve having a through-aperture adapted to be closed by the valve carried by the piston, and means for feeding the air past the piston and the piston-valve respectively, substantially as described.

3. The combination of the brake-cylinder, an auxiliary reservoir of larger diameter than 'f said cylinder, the brake-piston in the cylinder, the piston-valve in the auxiliary reservoir, said valve having a through-aperture and being adapted to engage the brake-piston so that the latter will close said aperture, and means for feeding the air past the piston and the piston-valve respectively, substantially as described.

4. The combination of the brake-cylinder, the piston therein, the auxiliary reservoir connected to the cylinder, thepistonvalve movable within said reservoir independently of the piston and adapted to engage said piston, and means for feeding the air past the piston and the piston-valve, substantially as described.

M 5. The combination of the brake-cylinder, the piston therein, the auxiliary reservoir,

When a partial release of the brake is made, the greater force Io5 l IIO of the piston-valve, the latter being movable independently of the piston, substantially as Io described.

HERBERT s. SMITH.

Witnesses:

A. L. RICE, GUY H. SALISBUEY. 

